1. Field of the Invention
The present invention relates to a coil assembly for a linear motor, especially to one that increases the contacting area between coils and the inner wall of a receiving slot of a base to promote the heat dissipation rate.
2. Description of the Related Art
Generally, the coil assembly for a linear motor without a core would have its coil unit covered by a resin encapsulated layer for further being received in an indentation of a base. However, since the resin encapsulated layer is made of the high polymer plastic, the heat dissipation effect is unsatisfied; especially, if the coil winding is electrified, the coil thereof is subject to being overheated.
In order to settle the overheated coil, “A Linear Motor without a Core” is issued by an R.O.C. patent no. I288521. Wherein, such disclosure is able to lower the temperature of the armature winding. Moreover, a rotor in the disclosure consists of an armature winding and a rotor installing platen. Herein, the armature winding includes a plurality of coils, and the rotor installing platen provides a support for the armature winding. Further, a stator comprised in the disclosure is composed of a permanent magnet with multiple magnetic poles and a yoke. Thereby, the permanent magnet would clasp the left and right sides of the armature winding to form the linear motor without a core. An indentation is further defined under the rotor installing platen, thence permitting an upper portion of the coil to insert into the indentation on the rotor installing platen. Additionally, a space is disposed near a lower portion of the coil for executing the connection between the coils or between the coils and a leading wire. However, some shortcomings exist in such invention:
Conventionally, the coil is directly inserted in the indentation on the rotor installing platen for promoting the heat dissipation rate. However, the daily application of the linear motor without a core has an increasing demand. Namely, the current flowed in the coil requires higher. If a certain thrust is generated in accordance with the daily increased current demand, the corresponding current value employed on the coil winding should be enhanced to the square of the current value. As a result, such invention needs to more extend the heat dissipation efficiency thereof.